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Thursday, July 26, 2012

Updating While Waiting: The Dilemma

Those
of us who follow the plans for future planetary exploration are waiting for two
breaking events.The first, expected in
July based on NASA’s previously announced schedule but subject to delay, is the
announcement of which mission it has selected for the Discovery mission.Either the interior of Mars, the
heterogeneity of a comet, or the surface of a Titan lake will be the focus of a
great mission.(It may say something about
what kind of person that I am, but whatever is announced, I will feel that two
great opportunities have been passed over.)

The second event, with a firm schedule
down to the minute, will be the success or failure of the Curiosity rover’s
landing on Mars. While this may seem
like current rather than future planetary exploration, a success will encourage
more funding for planetary missions while a failure will do the opposite. SpacePolitics.com quotes the head of NASA’s
planetary science program on the importance of this landing in a speech given
to lunar scientists, “’It’s absolutely essential
for everybody in this room to recognize that, whether you’ve been following
this or not, this is going to have an enormous effect on you, personally,” he [Jim
Green] told a room filled primarily with lunar scientists. “Whether it’s
successful or not successful, it will have an enormous effect on the planetary
budget, and therefore, all of our careers… The landing of MSL will be
absolutely critical, and we really need to take note of what’s going to happen
here.”

So
while we wait, I thought I’d provide updates in this post and following ones on
a number of items that don’t quite deserve a post of their own.

First
up, published today, is a long article in the journal Science on the options
for exploring Mars. (Unfortunately, it’s
subscription only or can be purchased for $15.
You can read the first paragraph and follow the link to purchase.) Richard Kerr reports on the quandary that the
Mars program finds itself in. With the
exception of sample return and the exploration of Mars’ interior (the focus of
one of the Discovery missions in competition), all the major firsts for Mars
have been done (assuming the Curiosity mission is a success). So while future orbiters could carry better
versions of instruments and rovers could land in new places, the feeling is
that the results wouldn’t be revolutionary enough to compete with missions to
other worlds. Kerr quotes the head of
the Decadal Survey’s Mars panel on the value of future incremental missions: “[Phillip]Christensen [Arizona State University, Tempe]
says he would love to fly a souped-up version of the instrument [a better
multispectral imager] on a future [orbiter] mission. “But is that essential to
our understanding of Mars? I think not,” he says. “It wouldn't be
revolutionizing. You can do only so much from orbit, no matter how good your
spectrometer. We're pretty darn close to doing what you can from orbit.”

Kerr points out that other scientists disagree
with Christensen’s (and many others) view on the value of incremental
missions. John Grotzinger, the
Curiosity rover’s project scientist, for example, is promoting the idea of a
series of smaller rovers in the class of the Opportunity rover currently at
Mars but with significantly more advanced instruments (see below).

Kerr ends his article by pointing out that NASA’s
Mars program is becoming entangled with NASA’s human spaceflight program, which
has a long term goal of reaching Mars.
He finishes the article with an assessment of the risks of this
strategy: “In other words, planetary science would be riding human
exploration's coattails to Mars in the FY 2014 budget request. ‘That is fraught
with danger,’ Christensen says. ‘If you attach yourselves to human exploration,’
[Frances] Bagenal [University of Colorado, Boulder] says, ‘you end up
tailoring your science to address the needs of human exploration. Then they
change their mind. The lunar people have been down that road several times.’”

Another
article out this week from the journal Nature, explores the idea behind what an
incremental rover mission might do.
(Nature made this article freely available here.) In a previous posthttp://futureplanets.blogspot.com/2012/06/next-generation-mers-for-mars.html, I described ideas for
reusing the basic design of the Mars Exploration Rovers Spirit and Opportunity
and outfitting them with modern instrument suites (a lot of instrument
development has occurred since Spirit and Opportunity were designed). One idea would be outfit one or more rovers
with a new generation of instruments that can date Martian rocks to within a
few tens of millions of years. The article
explains how important these measurements would be, “If
chronology on the Moon is still uncertain, then Mars is a mess. The
crater-count method does not work as well there, mainly because the wind, water
and frost that sculpt the surface also erase craters… With a portable system,
researchers could decipher how long volcanism lasted on Mars and when it
stopped. They could find out when the planet's warm, wet and possibly habitable
environment gave way to the cold desert it has been for several billion years. ‘If
any evidence is found for life, we sure as heck will want to know when it was
there,” says [Hap] McSween [University of
Tennessee in Knoxville].’”

The article provides a fascinating insight into the process and
challenges of developing cutting edge capabilities for new planetary
missions. I highly recommend it.

Editorial
Thoughts: These two articles together highlight a tension in how science is
done. The easiest way to make big
discoveries is to simply be the first to go somewhere (or at least be the first
to bring a new type of instrument such as the first high resolution imaging spectrometers
in Mars orbit). The naturalists who
explored the world during the European age of discovery had a field day. Everywhere they went, there was a new
discovery waiting for them. (To get an
idea of what the opportunity was like, look up how many species the Scottish
naturalist David Douglas named for himself or had named for him in the Pacific
coast states of the U.S. https://en.wikipedia.org/wiki/David_Douglas_(botanist)). However, it has taken decades of intensive
science to follow up on these discoveries and to start to really understand the
geology, biology, and ecology of these areas.
In the Pacific Northwest, where Douglas was an early European explorer,
we didn’t even understand the ecological importance of old-growth forests until
the last two to three decades, and my colleagues are still trying to understand
many key facts how the develop and function.

Planetary
science has been in the lucky position of those European naturalists in being
able to make many astounding discoveries simply by delivering a spacecraft or
an instrument to a new place. The opportunity
for those relatively cheap and frequent missions becomes fewer with each new
mission. As a result, the planetary
community is left to decide whether to recommend less expensive missions that
do the yeomen’s work of filling in the details or propose the often expensive
bigger missions that do the new and extraordinary. I believe that the fear is that the
politicians may balk at paying hundreds of millions of dollars per mission for
the former and equally may balk at paying billions of dollars for the latter.

About Me

You can contact me at futureplanets1@gmail.com with any questions or comments.
I have followed planetary exploration since I opened my newspaper in 1976 and saw the first photo from the surface of Mars. The challenges of conceiving and designing planetary missions has always fascinated me. I don't have any formal tie to NASA or planetary exploration (although I use data from NASA's Earth science missions in my professional work as an ecologist).
Corrections and additions always welcome.